1. Field of the Invention
The present invention relates to artificial molar teeth which can be arranged easily when making a dental prosthetic appliance and are easy in mastication when wearing it as dentures.
2. Description of the Related Art
Arrangement of artificial molar teeth when making a dental prosthetic appliance required advanced skills and experiences. Therefore, it was difficult to arrange the artificial teeth in an appropriate positional relation. In particular, it was extremely difficult to arrange in a state as intended by the designer when designing the artificial teeth. Herein, the appropriate positional relation refers to a position where the function of the dentures can be fully exerted, and it is a state free from troubles in chewing, swallowing and eating food and speaking sound.
In the conventional artificial teeth, too much attention has been paid to natural teeth, and it was considered important to “copy” the natural teeth when making. To make stable dentures, it has been desired to arrange the adjacent artificial teeth easily. However, if made ideally in the designing stage of artificial teeth, a small error may be included in the fabricated artificial teeth. As a result, the artificial teeth may cause occlusal imbalance and disrupt arrangement and son on. In the conventional artificial teeth, accordingly, the surface state was largely changed by grinding largely after arrangement. It has been hence desired to develop artificial teeth easy in arrangement at proper positions and easy in adjustment, even if there are some defects in forming, in the arrangement of artificial teeth of upper and lower jaws.
PCT Application International Publication WO2004/096077 discloses artificial molar teeth, as artificial molar teeth for lingualized occlusion, in which all of four teeth including the maxillary or mandibular first premolar tooth, second premolar tooth, first molar tooth and second molar tooth are connected to each other. In these artificial molar teeth, a blade form is imparted to the lingual cusp of the upper molar teeth while protrusions are formed in the buccal cusp of the mandibular second premolar tooth and second molar tooth. The sliding gaps between these artificial molar teeth and the maxillary artificial molar teeth opposing thereto are demarcated, and a groove extending through the four teeth is formed at the basement side of these four connected artificial molar teeth. This groove has openings at the end of the first premolar tooth and the end of the second molar tooth.
However, PCT Application International Publication WO2004/096077 relates to connected teeth which are artificial molar teeth with a focus on masticatory function because the blade is provided in the lingual cusp of the maxillary artificial molar teeth, and the protrusion is formed in the buccal cusp of the second molar tooth. Moreover, because of the connected teeth, application in arrangement is poor, and it is not easy to arrange in each clinical case.
Japanese Unexamined Patent Publication No. 2003-38525 discloses an artificial tooth assembly having a maxillary portion and a mandibular portion. The maxillary portion includes a maxillary artificial tooth portion having maxillary artificial teeth, an upper side holding tool for holding the maxillary artificial tooth portion, and a bump portion as upper side positioning means provided in the upper side holding tool. Similarly, the mandibular portion includes a mandibular artificial tooth portion, a lower side holding tool, and a groove as lower side positioning means. The maxillary portion and the mandibular portion are positioned in an appropriate occlusal state when the maxillary artificial teeth and mandibular artificial teeth are engaged by the bump portion and the groove. The artificial tooth assembly having the above configuration lessens the working labor of planting of artificial teeth, and shortens the term for making the dentures in appropriate occlusal state, and enables the planting in a simple structure and easy process, without requiring troublesome and individual positioning operation, and without demanding any particular consideration on the appropriate occlusal state.
In Japanese Unexamined Patent Publication No. 2003-38525, however, since the artificial teeth are arranged by using the holding tool, it is difficult to apply to various arrangements of artificial teeth in individual clinical cases.
Japanese National Publication No. 2001-506525 (WO98/26728) discloses an artificial tooth arrangement device made of a flexible material, and having a tooth support ribbon molded so as to form an arch shape generally corresponding to the upper or lower natural dental arch. The artificial teeth are detachably mounted and arranged in a manner profiling the natural dental arch on the support ribbon so that the grooves of the teeth engage hooks of the ribbon.
However, the arrangement device of Japanese Unexamined Patent Publication No. 2001-506525 requires an arrangement jig, and it can be applied in making dentures of a full mouse, but otherwise it can be hardly applied in various artificial tooth arrangements in clinical cases.